Turnip

Turnips are usually sown directly into the garden, since root crops establish best without transplanting, though transplants can also be used. Seed is set about half an inch deep in rows roughly 18 inches apart, with plants thinned to about 3 inches apart after germination, which takes about five days. They need full sun, rich well-drained soil that has been deeply worked, and consistent watering, and they are planted in mid- to late summer or over the cool season for a fall or winter harvest, since the crop tolerates frost and even light freezes.

Keeping the growing area weed-free helps turnips establish, and steady moisture and fertility matter through the season: plants that go short of water or nutrients, or that are left too long before harvest, tend to develop woody, fibrous roots.

Turnips draw a range of insect pests, including aphids, whiteflies, flea beetles, and caterpillars such as cabbage loopers, cutworms, and beet armyworms, along with slugs and snails feeding on foliage. Disease problems include club root, white rust, leaf spot, and rots such as damping-off and bacterial soft rot.

Beyond pests and disease, the root itself can suffer a physiological fault: insufficient water, inadequate fertilizer, or harvesting too late all push the root toward a woody, pithy texture rather than a disease as such.

Roots are best pulled while still young, at about 2 to 3 inches across; left to grow larger they turn pungent, pithy, and stringy, and flavor is said to improve once the roots have been touched by frost. Roots typically reach maturity 40 to 60 days from sowing.

Greens can be harvested continuously through the growing season without waiting for root maturity, though care should be taken not to strip a plant too heavily at once.

Culinary: Both the root and the leaves of the turnip are eaten raw or cooked, with young leaves suited to salads and older leaves sautéed, making the plant a dual-purpose vegetable rather than a root-only crop.

Fodder: Turnip cultivars bred for larger roots, known as forage turnip, have been grown as livestock feed in Europe and Asia for centuries, valued for extending the grazing season into autumn; the tops are notably high in crude protein and digestible dry matter. Because the roots, leaves, and especially seeds contain sulfur compounds, heavy consumption by livestock, particularly horses, has been linked to digestive upset and thyroid irritation.

The turnip is counted among the oldest cultivated vegetables, with a history of being eaten stretching back some four thousand years, and its wild relatives trace to Eurasia. In Ireland, turnips carried a distinct cultural role before the crop's introduction to North America: local tradition holds that the first jack-o-lanterns were carved from turnips, a practice later replaced by pumpkins once it took root in America.